JP2008238639A - Manufacturing method for ceramic green sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a ceramic green sheet capable of preventing generation of delamination between a ceramic green sheet and a conductive pattern in case of laminating both. <P>SOLUTION: The manufacturing method of the ceramic green sheet has the ceramic green sheet-forming process comprising the process of applying slurry composed of a ceramic material as a major component on a support substrate 13 so that its thickness is uniform and the process of drying the applied slurry to form the ceramic green sheet wherein the slurry applied on the support substrate 13 is humidified under humidity of 50 to 80%. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a ceramic green sheet for a multilayer electronic component used in various electronic devices such as digital devices, AV devices, and information communication terminals.

  A conventional method for producing this type of ceramic green sheet is to prepare a slurry by mixing a magnetic material powder mainly composed of ferrite and the like with a binder mainly composed of polyvinyl butyral and an organic solvent. Was molded into a sheet by the doctor blade method to obtain a ceramic green sheet.

As prior art document information relating to the invention of this application, for example, Patent Document 1 is known.
JP-A-6-77073

  When a multilayer electronic component is manufactured using the ceramic green sheet obtained by the above-described conventional method for manufacturing a ceramic green sheet, there is a problem that delamination is likely to occur.

  That is, when the ambient humidity fluctuates, the amount of water contained in the slurry also changes. When the ambient humidity is low, the amount of moisture in the slurry decreases, and therefore when the ceramic green sheet is formed by drying the slurry. In this case, the moisture does not evaporate so much that there is almost no pore (void) in the ceramic green sheet, and the sheet density of the ceramic green sheet is also increased. As can be seen from (Equation 1), the ceramic green sheet having a high sheet density has a low compression rate. Therefore, when the ceramic green sheet and the conductor pattern are laminated, delamination is caused between the conductor pattern and the ceramic green sheet. It will occur.

  In (Equation 1), the laminate density is obtained by punching a laminate in which a plurality of ceramic green sheets are laminated with a jig, and measuring the film thickness (volume) and weight.

  The present invention solves the above-described conventional problems, and an object of the present invention is to provide a method for manufacturing a ceramic green sheet that can suppress the occurrence of delamination between the ceramic green sheet and a conductor pattern. It is.

  In order to achieve the above object, the present invention has the following configuration.

  The invention described in claim 1 of the present invention comprises a step of applying a slurry having a ceramic material as a main component on a supporting substrate so as to have a uniform thickness, and a step of drying the applied slurry. In the method for producing a ceramic green sheet comprising a step of forming a ceramic green sheet, the slurry applied on the support substrate is humidified at a humidity of 50 to 80%. According to this production method, Since the slurry applied on the support substrate is humidified at a humidity of 50 to 80%, the ceramic green sheet in a state where moisture that evaporates later than the organic solvent is included in the slurry when the slurry is dried. As a result, fine pores can be formed at locations where the evaporated water in the slurry was present. The density of the Mick green sheet can be kept low. As a result, when this ceramic green sheet and the conductor pattern are laminated, the occurrence of delamination between the ceramic green sheet and the conductor pattern can be suppressed. Is obtained.

  In the invention according to claim 2 of the present invention, in particular, in the step of drying the slurry applied on the support substrate, the slurry is moved from the inlet of the drying device to the inside while pulling the support substrate toward the outlet of the drying device. In addition to inserting, the air heated from the vicinity of the outlet of the drying apparatus is sent into the interior of the drying apparatus, and the heated air is discharged from the vicinity of the inlet of the drying apparatus, and further humidified in the step of humidifying The air is discharged from the same location at the same time as the discharge of the heated air. According to this manufacturing method, the slurry applied on the support substrate can be dried stepwise, so that the ceramic It is possible to reduce the occurrence of cracks in the green sheet, and the ceramic green sheet with moisture in the slurry for a long time Since it can be molded, when this ceramic green sheet and the conductor pattern are laminated, the effect of effectively suppressing the occurrence of delamination between the ceramic green sheet and the conductor pattern can be obtained. is there.

  As described above, the method for producing a ceramic green sheet according to the present invention humidifies the slurry applied on the support substrate at a humidity of 50 to 80%, and therefore is slower than the organic solvent when drying the slurry. Ceramic green sheets can be formed in a state in which the water to be evaporated is contained in the slurry, and as a result, fine pores can be formed where the evaporated water was present in the slurry. The density of the green sheet can be kept low. As a result, when this ceramic green sheet and conductor pattern are laminated, the delamination between the ceramic green sheet and the conductor pattern can be suppressed. It plays.

  Hereinafter, a multilayer electronic component configured using a ceramic green sheet obtained by a method for manufacturing a ceramic green sheet according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an exploded perspective view of a multilayer electronic component constructed using a ceramic green sheet obtained by the method for producing a ceramic green sheet in one embodiment of the present invention, and FIG. 2 is a perspective view of the multilayer electronic component. is there.

  As shown in FIGS. 1 and 2, a multilayer electronic component configured using a ceramic green sheet obtained by the method for producing a ceramic green sheet in one embodiment of the present invention is obtained by heating the ceramic green sheet. First to fifth insulating layers 1a to 1e made of the magnetic material formed, and first to fourth conductor patterns 2 to 5 provided on the top surfaces of the first to fourth insulating layers 1a to 1d, respectively. And the second conductor pattern 3 and the third conductor pattern 4 are made to face each other, and these are integrated to form a laminate 7, and the first to fourth components are formed at both ends of the laminate 7. External electrodes 8a to 8d are formed. In this case, the first via 6a is formed in the second insulating layer 1b, the second via 6b is formed in the fourth insulating layer 1d, and the first via 6a is formed through the first via 6a. The conductor pattern 2 and the second conductor pattern 3 are connected, and the third conductor pattern 4 and the fourth conductor pattern 5 are connected through the second via 6b.

  Next, a method for manufacturing a ceramic green sheet according to an embodiment of the present invention will be described with reference to FIG.

  First, an ester and alcohol are added as solvent to a raw material powder mainly composed of ceramic, a binder is further added, and they are mixed by a ball mill to prepare a slurry. The slurry separated from the ball mill is put into a pressure-feed tank, defoamed while being stirred, and the slurry is sent from the pressure-feed tank to the liquid dam 11 while being controlled by a liquid level sensor so that the liquid level of the slurry is constant. The liquid dam 11 is located in the sealed coating part 12 with the humidity of the internal air maintained at 50 to 80%. Thereby, the slurry can be humidified at a humidity of 50 to 80%.

  Next, the slurry put in the liquid dam 11 is applied to the upper surface of the support base 13 made of a strip-like PET film by a doctor blade method so as to have a uniform thickness. At this time, the humidified air 14 in the coating unit 12 is taken into the slurry.

  Next, the slurry and the support substrate 13 are inserted into the drying device 15 through the inlet 15b of the drying device 15 while being pulled toward the outlet 15a of the drying device 15 at a constant speed.

  In this state, warm air (heated air) 16 heated to about 75 ° C. is sent from the vicinity of the outlet 15 a of the drying device 15 into the drying device 15, and a discharge unit provided near the inlet 15 b of the drying device 15. The hot air 16 is discharged from 17. In this case, since the warm air 16 is fed only from the vicinity of the outlet 15a of the drying device 15, the temperature of the warm air 16 gradually decreases toward the discharge unit 17, thereby drying the slurry stepwise. Therefore, the generation of cracks in the ceramic green sheet can be reduced.

  Further, the humidified air 14 in the coating unit 12 is also introduced into the drying device 15 from the inlet 15 b of the drying device 15, and is discharged together with the warm air 16 from the discharge unit 17. Thus, since the slurry can be exposed to the air 14 containing moisture for a long time, moisture can be included in the ceramic green sheet for a long time, and thereby, the delamination between the ceramic green sheet and the conductor pattern can be performed. Generation of lamination can be effectively suppressed.

  Finally, the slurry and the support base 13 are led out from the outlet 15a of the drying device 15 while being wound up by the sheet winder 18, thereby forming a dried ceramic green sheet made of uniform slurry.

  Then, by laminating the ceramic green sheet obtained as described above and a predetermined conductor pattern, and heating and pressurizing, a multilayer electronic component as shown in FIGS. 1 and 2 can be obtained. It is.

  FIG. 4 is a diagram showing the relationship between the sheet density of the ceramic green sheet obtained by the method for manufacturing a ceramic green sheet in one embodiment of the present invention and the humidity in the coating part.

  Here, the method of calculating the sheet density of the ceramic green sheet is to dry the slurry, peel off the dried slurry immediately before the sheet winder 18 from the support base 13, cut it into a predetermined size, ) And measuring the weight.

  As is clear from FIG. 4, when the humidity in the coating part 12 is 50% or more, the sheet density of the ceramic green sheet is lowered. Therefore, from (Equation 1), the humidity in the coating part 12 is 50%. In the above case, it can be seen that the compression rate is high.

  It has also been found that cracks are likely to occur during drying in a very high humidity environment where the humidity exceeds 80%.

  From these results, if the slurry applied to the support base 13 is humidified at a humidity of 50 to 80%, the slurry contains moisture that evaporates later than the organic solvent when the slurry is dried. The ceramic green sheet can be molded with this, and because fine pores can be formed where the evaporated water in the slurry was present, the density of the ceramic green sheet can be kept low, As a result, in the case where the ceramic green sheet and the conductor pattern are laminated, an effect of suppressing the occurrence of delamination between the ceramic green sheet and the conductor pattern can be obtained.

  The method for producing a ceramic green sheet according to the present invention has an effect that it is possible to suppress the occurrence of delamination between the ceramic green sheet and the conductor pattern, and in particular, digital equipment, AV equipment, information This is useful for laminated electronic components used in various electronic devices such as communication terminals.

1 is an exploded perspective view of a multilayer electronic component configured using a ceramic green sheet obtained by a method for manufacturing a ceramic green sheet according to an embodiment of the present invention. Perspective view of the same multilayer electronic component The schematic diagram which shows the manufacturing method of the ceramic green sheet in one embodiment of this invention The figure which shows the relationship between the density of the ceramic green sheet obtained by the manufacturing method of the ceramic green sheet, and the humidity in a coating part

Explanation of symbols

DESCRIPTION OF SYMBOLS 13 Support base body 14 Humidified air 15 Drying apparatus 15a Outlet of drying apparatus 15b Inlet of drying apparatus 16 Heated air

Claims (2)

A ceramic green comprising a step of forming a ceramic green sheet comprising a step of applying a slurry having a ceramic material as a main component on a supporting substrate to a uniform thickness and a step of drying the applied slurry. In the method for producing a sheet, a method for producing a ceramic green sheet in which the slurry applied on the support substrate is humidified at a humidity of 50 to 80%. In the step of drying the slurry, the slurry is inserted into the inside of the drying device while pulling the support substrate toward the outlet of the drying device, and air heated from the vicinity of the outlet of the drying device is inserted into the inside of the drying device. And the heated air is discharged from the vicinity of the inlet of the drying device, and the humidified air in the humidifying step is discharged from the same location simultaneously with the discharge of the heated air. Item 2. A method for producing a ceramic green sheet according to Item 1.

Images